“Then, which of the Aalaa’ (wondrous acts of power) of the Lord of both of you will you both deny/declare to be false/dismiss/undermine?”.
رَبِّكُمَا combines رَبّ with the dual second-person pronoun كُمَا, directing speech to two addressees. The second person here creates تَقْرِيب (bringing near) as opposed to third-person تَبْعِيد (distancing). The address becomes immediate and unavoidable for those being addressed.
تُكَذِّبَانِ (from تَكْذِيب) conveys declaring truth to be false, invalid, or baseless — aiming to discredit or undermine. In the context set by the previous surah (Al-Qamar), such تَكْذِيب led to destruction, underscoring anger and threat in this direct address.
Four kinds of signs are in view — revelation, ourselves, the heavens, and the earth — with emphasis on order, balance, and beauty in all of them.
الرَّحْمَنُ عَلَّمَ الْقُرْآَنَ — the Qur’an is taught by Allah. Denial is to undermine that it is from Him.
Our creation and الْبَيَان — the taught capacity for clear, coherent speech and articulation.
Stars and sky — their order, balance, and beauty.
The world around us — its order, balance, and beauty.
Denial spans multiple aspects at once — not just the things themselves but the order, balance, and beauty permeating revelation, ourselves, the heavens, and the earth.
Outside this repeated ayah in Ar-Rahman, آلَاءِ appears in An-Najm and in Al-A’raaf (69, 74).
While favours can be specific to humans, the power in Allah’s acts is witnessed and appreciated by both humans and jinn.
This ayah drives toward appreciation — recognizing Ar-Rahman, the Qur’an as Rahmah, our creation as Rahmah, and the gift of الْبَيَان as Rahmah — expressed through:
Second-person dual draws the listener in — it cannot be ignored.
Not mere denial — an attempt to invalidate and undermine the truth.
From “favours” to the broader wonders of Allah’s power and creation.